Boston Computer Society - Sinclair Timex User Group Newsletter

GOOG The Boston Computer Society

SINCLAIR-TIMEX USER GROUP NEWSLETTER

Volume 3 Issue 3

POLYGONS
by John Kemeny

Gae of the beet features of the
T/S 2068 computer is ite ability
to create and display high
resolution graphics. There are
Commands in T8 BASIC to PLOT
points, DRAW lines, and even
make CIRCLEs and arcs. This
article will present subroutines
to draw equalateral trianges,
squares, penta~hexa-hepta- octa-
nena-dece~ and other polygons.

Polygon shapes have equal sides
and equal angles. In addition,
we hope ta demonstate in this
article something about
developing programs and making
them more efficient.

Let’s start with the inputs (see
figure 1). We need to know the
coordinates for the center, 0,
and the radius, OA.

10 INPUT “CENTER’S
COORDINATES"* X,Y
20 INPUT “RADIUS"’R

The x-coordinate should be
between © and 255, and the y
between O and 175. Aleo, the
radius should be smell enough so
that the polygen wan't go aff
the ser@an, 2.8., we wan't de
what's known ae “clipping.” To
anforce cur “shoulds" we can add
the following Lime:

25 IF X-R<O OR X+R>295 GR y-R<o
OR ¥+R>i75 THEN GOTO 10

We aisc need to know the number
of sides.

POLYGONS page 6

March 1994

FEBRUARY MTG
HIGHLIGHTS

With Sue at home in Waterbury
recuperating from her autorgobile
accident, the February meeting
was chaired by John Kemeny. He
spoke briefly about the propsed
new library policy, asked for
volunteers, told us about a
machine code newsletter in
Albany NY, and plugged the March
meeting of our machine language
group.

The growp’s library is now being
kept at the BOS office (1 Center
Plaza, Boston), I will no
longer be brought te aeetings
and, if we can get a veluntear
to be the librarian, things can
b@ chacked out from thar@ ane or
twa nights a month. As always
the group needa volunt#ers for
various gabs. John is organizing
@ project to index #11 the
exchange newsletters we've
received, and we naed volunteers
te help put out cur own
newsletter.

The Albany machine language
group associated with Bonnie and
Clyde Goftware ia publishing a

HIGHLIGHTS page 4

2 fs

1c REM

TAKE THE MONEY AND RUN

Timex wae invelved with Sinclair
computers from the very
beginning. Early Sinclair
@achines were manufactered to
Sinclair specs at a Timex
factory in Scotland. One can
speculate that this close
association led to Timex’s later
role in this story.

Now Timex hes dropped out of the
personal computer market and it
makes me wonder about their
motivations from the very start.
Thare’s no evil in a company
finding itself in financial
difficulties and having to close
a part of their business to save
the rest. But that’s only if
the company was participating in
the market in good faith in the
first place. Texas Instruments
had to abandion their home
computers for these reasons but,
even with all their mis-steps, I
believe they really wanted to
build great computers. That
sadly, is not always the

Timex brought nothing ta the
microcomputing community. They
never mad@ any sericue attempt
te premate the value of the
Sinclair products nor to support
the community of users that grew
around the machine When there
was money to be made Timex
accepted it and when things got
rough they pulled out.

I am a capitalist by nature. I
have absolutely no objection to
on@ making money, lots of money.

But to make it fairly you should
produce @ valuable commodity.
Make some good contribution to
the marketplace. I have no
inside information, but I feel
that Timex never had any
intention of adding something to
the home computer cemmunity.
They wore in it to meke a fast
buck. ALL they wanted to do was
take our money. That’s net good
capitalism and I think it’s no
coincidence that Timex
ultimately failed. And perhaps
no surprise that the whole Timex
Corp is in trouble. As for me
I’m now giving serious thought
to ever again using other Timex
Products. How can their actions
in computers not reflect on
their attitude about all their
other customers and products.

I’m very dissappointed with
Timex.

A Final Note:

The grape vine says that
Sinclair Research is on the
verge of signing a U.S.
distribution agreement for the
Quantum Leap cemputer with The
Betty Crocker Company.

& source in Sinclair is reported
to have said that, "this
agreement will pave the way for
the QL to be sold in thousands
of grocery stores and
supermarkets around the

country."

ee ee er ee

©The

@ Boston
Computer
Society

This newsletter is produced to
inform group members of the
agenda and logistics of future
meetings, as well as to recap
and amplify the information
provided at the meetings. It
also provides a forum for
members and interested parties
to communicate what thay have
learned or developed relating ta
Sinclair and Timex computing.
Meetings are open to the public
(non-member admission is $3);
however attendees are encouraged
to join the Beston Computer
Society (BCS) This newsletter
is free to members. Back issues
are one dollar each.

DIRECTIONS TO MEETING: The S-T
User Group meets in the Large
Science Auditiorium (Room 8/2/
009) of the University of
Massachusetts, Boston Harbor
Campus. It i# located only 3
miles from downtown Boston and
easily accessible by public and
Private transportation. From
the nerth or west, take the
Southeast Expressway to Exit 17.
Turn left ente Columbia Road.
Follow construction signs ta get
to Morrissey Boulevard in the
direction of UMASS and the
Kennedy Library. Bear right on
traffic island, get in the right
two lanes, following UMass/
Boston signs. Turn left at the
light into Campus. From the
south, take Morrissey Boulevard
northward to the campus. On the
META, take the Red Line (Ashmont
Train) to Columbia Station.
Transfer to the free University
shuttlebus in the T parking lot.

The Sinclair Timex User Group

Sue Mahoney
Director

c/o BCS Office
or 203-785-2699

Jack Hodgson
Publisher /Editor
P.O. Box S26
Cambridge, MA 02238
617-354-7899

John Kemeny

User Group Correspondent
284 Great Road, Apt. DS
Acton, MA 01720

Allan Cohen
Meeting Coordinator
617-961-3493

The Sinclair Timex Newsletter is
published monthly by the
Sinclair Timex User Group of the
Boston Computer Society.
Membership in the BCS is 624 eer
year which includes a
subscription to its magazine
“The Computer Update" and
subscription te two of its group
newsletters (such as this one).

Advertising space is available
in this publication on a
limited, first come ¢irst served
basis. The rate is $40 per

Quart Page. At this time no
other |‘ sizes are available.
For detailed rate and discount
information contact the
Advertising Manager or the
Publisher.

7 wma miaemmaansearnerasmamee aie

HIGHLIGHTS continued

newsletter. Free sample copies
are available if you send them a
card requesting it. Ron Barnard,
Bonnie and Clyde Software, 36
Tanglewood Rd., Albany NY 12205.

Hanry April of EZ Kay
demonstrated Upload 2000. Thie
ie @ program for the TS2068
which helps you to convert
TS1000 family programs to run on
the 2068. The main Limitation
ia that the source program must
be 100% in BASIC. Also some of
the TS1000 commands have to be
translated by hand after the
UPLOAD program has done most of
the translation. Henry also told
us that he will be distributing
the Compusa Disk Drive system
for the T81000/1500 computers.
EZ Key, Suite 75, 711 Southern
Artery, Quincy, MA 02169.

dack Hodgsen took a couple of
quick show-of-hands surveys of -
the audience. Of the 2% people
there: 9 owned T82068’s, 3 owned
TS1500’s, and near 100% owned
T81000/ZXB81i's. Roughly 80% had
been to 6 or more meetings, 20%
head been to less than 6 and
about 6-8 people were there for
the first time.

THE DEMISE OF
TIMEX COMPUTEF
CcCoRrFoORAT EO

(ar What is To Become Of The
Timex Sinclair Owners?

By Susan C.T. Mahaney, Director,
Sinclair Yimex User Group

I was one of the first people to
learn that Timex was getting out
of the personal computer retail
market. A friend of mine, who
was working there called me to
tell me the news, just minutes
after she received the word
herself.

My first reaction was that it
wae hard to believe, although
Timex had suffered some
setbacks, it was looking like
they might make it. Especially
with all the good reviews of the
TS 2068 and the new gland
that were ebout to be markete:
@.G., the adem, the 80 coluan
printer, the microdrive.

I remember initially feeling
like a member of my iamediate
family had died. I personally
have been involved with both
Sinclair Research, Ltd. and
Timex Computer Corporation since
August of 1981. I had observed
first hand the excitment and
enthusiasm that the Sinclair and
Timex computer products had
generated from its owners and
users, not to mention all of the
more than 500 third parties that
had developed products to
suppert the TS computers.

In addition I had worked for
Timex and experienced being laid
off myself, I knew exactly what
those 24 people were feeling,
after being told to get their
personal belongings, since they
ne longer worked there. Some
people, like my former boss had
worked for Timex for 23 years,
it is mot easy to pick up the
pieces and go on. To these
people I wiah thea the best.

After a good night’s sleep, I
began to realize that this did
net rapresent the end, in fact
after reading several accounts
of this dismantling in various
hevwspapers and talking with a
variety of individuals,
including Timex and Sinclair
spokespersons I was feeling much
more hopeful. Some of the
reasons for this included:

1. Sinclair is still in
business. We have an unusual
situation in that Timex was the
distributor for the computer

Bc. ee Lo OT eee

eniy in North America and a few
European countries. Sinclair
Research is still marketing the
2X1 and the ZX Spectrum in the
United Kingdom and the rest of
the world.

2. Sinclair's newest computer,
the GL or the Guantum Leap has
been very well received in the
UK. Sinclair Research will be
marketing it he in the US this
fall along with their flat
screen tv.

3. Mike Jacobi, the Marketing
Director for Timex, stated that
the marketing and/or
manufacturing rights for the TS
2048 are up for negotiation,
which means that either Sinclair
could get the rights back fer
the TS 2068 or some third party
could get the rights to the
computer.

Presently, Sinclair Research
denies any intention to market
any computer but the @L, but f
have seen this type of situation
change before. Alss, the
opportunity for a third party ta
step in could mean that an
existing company could come in
and take over the marketing
rights or a new company could be
formed of individuals who had
the right combination of capital
and understanding of the TS
comaunity.

This could work to the benefit
of the present owners and third
party manufacturers/marketers.
With the right company in
charge, we could see even more
cooperation in dissemination of
information between these
groups.

Only time will t@il, in the
meantime, we cannot think that
this whole issue is over, this
is not like Texas Instruments
announcing that they are getting
out of the personal computer

MAHONEY

market. There are a few more
variables at play here.

What are we to do in the
meantime? For one thing, Tf
think that we have to unite.
Particularly user groups, we
need to form a tighter network
of communication between our
aeabers as well as between user
groups across the country.

One concrete suggestion that I
can give is for user group
directors to poll their meebers
either formally or informally to
determine which usere are still
interested in contining with
their Timex Sinclair computers.
Then, if we could gather this
data to disseminate it to the
third parties and/or the. eny
perspective investors for the
Timex marketing rights, we would
be able to document that there
ig a viable market out there!
That it is worth someone
investing more money for product
development and suppert for TS
related software and hardware.

Ae for Timex’ plans for the
future, they will continue te
hener the warranties on their
existing equipment, and they
will be selling off their
Present inventory which includes
TS 1500, TS 2068, limited
supplies of their new aodem, and
existing software. The fate of
their 60 column printer and
their microdrive are right now
en hold, with no plans to market
either of the latter two
products. Basically, anything
that was produced prior to the
announcement will be made
available, but no new product
development in the computer area
is in the wind for new. a
qualify my statement because [
have seen things change too many
times to consider anything

next page

Peace aa

MAHONEY continued

associated with @#ither Sinclair
or Timex as final.)

Il recieved many calls from TS
owners, third parties, and the
press, from all over the country
and the UK, expressing concern
about what the future will be
for the owners of the Timex or
Sinclair cemputers. My answer
hes been that we need te hang in
there, not to give up, and to
remember that the dust has not
settled. We have an opportunity
to influence the future of the
Timex Sinclair line, by showing
that there ia a strong
enthusiastic market still out
there!

Our group will be glad to act as
@ clearing house for

di mination of information
relating to the Timex or
Sinclair computers. You may
contact Jack Hodgson (617-354-
7899) or myself (203-755-2699)
regarding questions, rumors,
ideas and of course support.
This ig a time when we all must
pull together and demonstrate
our interest.

POLYGONS continued
30 INPUT “NUMBER OF SIDES"'N

Finally, if we want to be able
to draw polygons in any
orientation, @.g°, & 4-gon ae
either a square or a diamond, we
need an initial orientation:

40 INPUT “ORTENTATION"’

For angles, computers generally
use radians instead of degress,
that’s what the Sinclair-1: max’
expects for their trig
functions. There a 2aPT
radians in 360 degrees. If we
want to enter the orientation ir
degrees, it is a simple matter
to convert it.

45 LET F=PSPr/iso

Figure 1 - HEXAGON

From now on we’ll consider all
angles in radians. We can
develop our algorithm using 4
little trigonometry.

(I4 you want to create computer
graphics, you shouldn’t have
slept through those trig classes
in high school.)

We'll draw N sides, sa:
100 FOR I=i TON

From figure 2 we can see how to
PLOT the initial point, A.

110 PLOT X+ReCOS P,Y+ReBIN FP

a ae

To gat from A te B we have to
draw the vector Bef. Since we
have N telices in our poelygen
"pizza" and 2&PI radians par
“pi@" (2 pi’s in 17), gach
slice, like angle BOA, has 2*PI/
N radians. Thus drawing vector
B-A igs

120 LET GeP+2aP1/N
130 DRAW R&(COB O-COS P), R&(SIN
Q-SIN P>

Te continue drawing the pelygen
we need to repeat (iterate) this
step using the point B as our
starting point. We can
accomplish thia by changing the
"old" initial angle P.

140 LET P=Q
150 NEXT I

This is our first algorithm.
Stop and try it. Enter 80 and
80 for the center, £0 for the
radius, @ for the number of
sides, and PI/@ radians (or 22.5
Gegrees) for the crientation.

This algerithm ise
straightforward, but not very
efficiant. To make it run
faster we can try to shorten the
work done inside the loop. This
may lead te a lenger
initialization, but it saves
execution time because the work
done ingide the loop isn’t

B A

®

Figure

repeated, For example, let’s
add line 50 and change 120%

SO LET V=2aPL/N
120 LET QeP+V

This saves some calculation
time. But our ra@al problem is
that each iteration of the loop
raquires six trig functiona (SIN
and €OS) to be evalueted. Can
improve on thie? (Look at figure
3. Note that the length of @ach
vector is the same. Call this
length &. Alse nete that the
angle of the vectors, call it T,
kee changing by 2&@PI/N radians
in wach iteration (going
counterclockwise). Let’s aadify
eur algorithm by changing line
i30 and adding i35¢

130 DRAW SsCOS T, 88SIN T
135 LET T=T+y

We must remember to initialize 8
and T (derivations are left as
exercises tor the reader).

60 LET Se2tReSiniv/2)
7O LET TaP+PI/2+v/2

In addition, since & is na
longer used in ling 130, we can
consolidate by deleting ling 140
and changing line 1206 tor

POLYGONS next page

S EE

POLYGONS
120 LET Pep+y

continued

There is a second, faster,
algorithm. Let's leok mext at
moving the PLOT statement
Outside the leap. In theory, a
new side starts where the
previous one left aff. But the
fact that we are working on a
high, yet finite, resolution
computer, and not an ideal
mathematical plane, can get us
in trouble. Because in practice
@ roundoff may cause our point
to be one tiny pixel off.
Unfortunately, this condition is
cummulative over the sides, so
the net result can be a polygon
that doesn’t close properly.

But de net abenden hope! For
small values of N the effect is
negligibles and polygons with
many sides aren’t really
distinguishable from circles
anyway. So, to create this
third algorithm, move line i110
to 80 and delete line 120.
Notice how little is left in the
loop. Further speedup is
possible. For example, we could
replace the FOR/NEXT control
structure with an IF THEN and
GOTO. Another idea is to use
table lookup methods to compute
the trig functions. Finally, we
could always resort to machine
code. Having identified and
boiled down the bottleneck, i.e.
the loop, greatly simplifies
uging machine code far the
problen.

Let’s finish with a flourigh.
Add a new input and change line
SO tor

49 INPUT “HOPS""H
SO LET Ve2aPISH/N

Try center 80 and 80, radius 60,
sides 5, orientation 18 degrees,
and 2 hops. Why do you think we
called it "haps"?

FIMAL POLYGON ALGORITHM

10 INPUT “CENTER? Ss
COORDINATES"? x, ¥

20 INPUT "RADIUS"*R

25 IF X-R<O OR X+R>255 OR Y-R<O
OR Y+R>175 THEN GOTO 10

30 INPUT "NUMBER OF SIDES*"?N
40 INPUT "ORIENTATION" 'P

45 LET P=PsP1/1680

49 INPUT “HOPS"’H

SO LET Ve2sP18H/N

60 LET S=2aRaSIN(V/2)

70 LET TaPsP1/24y/2

80 PLOT X+R&COS P, Y+RESIN P
100 FOR [=1 TON

130 DRAW S8COS T, S&SIN T
135 LET TeT+v

150 NEXT I

MACHINE LANGUAGE
GROUP HIGHLIGHTS

Mitch Russo of Zilog, who was
scheduled to speak to us in
March was taken il1 and hie
appearance will be rescheduled
for a later month. In his place
wa held a free form discussion
on a number of M/L tepics.
Answering each other’s questions
and passing on bits of
information.

The bulk of the evening was
occupied by Dave Miller telling
us about his experiences working
with EPROM’s (erasable
programmable read only
memories). Dave is designing
applications that will load
instantly by using cartridges
instead of cassettes.

Also he’s taken the entire
TSi500 ROM, corrected the ‘buga,
added a couple of custom
features and put it inte his
TSi900 computer. He is working
with an EPROM burner which he
built from plans in the ill-—
fated SQ magazine. He says he
uses mostly Intel 2716 and TI
2516, 2K X 8, EPROMS. For more

iene ecamancant

infe about Dave’s work you can
contect his through this
newsletter ar at cur next M/L
meetings

Speaking of the next meeting.
Because Bob Heath has aoved to a
new ignment it will ne longer
be possible for us to meet at
ITEK. He is currently looking
for a new location (any
suggestions?). In the aeantine
the April meeting has been
cancelled. Check this column
next month for the new location
or call Jack Hodgsen (617-354—-
7899)

THE WORM TURNS
by Will Stackman

This adaptation of a perennial game
format features the fastest movement
progranmable in BASIC on the Sinclair.
Characters are POKEd directly into the
portion of the memory beginning at 16396
known as the Display File. Scoring occurs
when positions in the same file are PEEKed
to see if they are already occupied.

The listing is annotated using variable
names which can be abbreviated to one
letter for typing in. Timing Loops are
used instead of the PAUSE command. The
PRINT staements after line 900 indicate
bytes used by this program. As given WORM
will run in 2K or 16K on a T/S 1000.

For 1K ZX81's, omit instructions and
scoring messages as well as auto-run,
You may want to remove one row from the
playing field as well.

The INKEY$ routine in line 110 is
perhaps the shortest way to implement
all four directions in one statement.
Other characters may be POKEd into the
field, but some of these will trigger
lockup or a crash.Line 110 can also be
adapted to work with a joystick such
as described elsewhere in this issue.

This approach to manipulating the
Display File is worth investigating as
the first step towards understanding the
machine code possibilities of our
machines,

use FoRRERTRE: TO Move = To @.
KEY "@" TO @urT

2 ERINT AT 2.83" enous fosneUEs
(Paya s 143 "USE ARROUS FO hose

TO'E. KE Tae
“2 FOR L=1 To 100

NEXT L

cLs

FAST

aah SCORE = Dy

PRINT "SCORE="; sco
LET _WORM=44PEEK 16596-2560
EEK 18397
S@ LET PLACE=voRM
6@ LET ASTERIX=PLACE+RNDes2e9
oracke IF PEEK ASTERIX<>128 THEN G
ae POKE Gegnnase isi
8@ POKE WORN,138
91 REM POKE igs” = HARDER

208 LET MOVE =VoOR:

118 Ler WORM = NORM+ CINKE
S34 (INKEY$="6") - CINKEY §=" }-33¢
CINKEY $=" 7")

220 IF INKEYg="Q" THEN GOTO 2590
Baan IF PEEK WORM=151 THEN oT

er IF PEEK WORM<}428 THEN LET
VORM=MOQVE

288 GOTO 8a

280 POKE WORM, 188

201 REM POKE 142 = HARDER

2128 LET SCORE= SCORE+10

215 PRINT AT 18,6; SCORE

Po GOTO 68

IF. SCORE «180. .THEN PRINT AT

185 qe: “TRY HARDER

ass IF SCORE <ip0 AND SCORE<ise@
ply PRINT AT 1@,48;"Go0D, co &

IF SCORE::1isa THEN PRINT aT
20.10," 45 LENT s"

SP GI CINI Hb =
ee

"BM

1 Onmmnsrsieesieee tony egeae es

GRAPH isk
by Mark Tepper

Here is 4 program te draw a bar
graph. When it runs you aust
enter 20 numbers, greater than 0
but less than 40, My goal in
writing the program was to keep
it as short as pousible, thus it
do@sn’t offer fancy borders,
variable range for numbers, etc.
The program illustrates «
Plotting technique you can use
in other programs.

10 REM 22% TS1000 GRAPH PROGRAM
20 LET Y = 4

30 DIM A(40)

40 FOR T = 1 TO 20

SO INPUT ACT)

40 NEXT T

120 LET T = T+i

130 LET Y = Y42

140 NEXT Z

150 PRINT AT 26,0; “10°
160 PRINT AT 12,0) "20"
170 PRINT AT 6,04 "30"
180 PRINT AT 1,03 "40"

$$ |

In the “Iet’s start a pusor”
dept:

MAGIC NEXUS STirs
4MiD L@NGUISH

(The above ¢itle is a wender¢ul
anagram for SINCLAIR-TIMEX HUGS
SAMBUNG AID.)

Let me slaborate on this
potentially good news. The
March 12th edition of Electronic
News reported that Sinclair
Research Ltd. hae signed a
licensing agreement with Samsung
Electronics of South Korea
wherein Samsung will assemble

and market the ZX81 and Spectrum

computers in South Korea.
Samsung will use Sinclair parts
and expects products by the
fourth quarter.

What does this mean te the Timex
~leas U.S. market? There are

three more ingredients needed to
make this into a truly gre
rumor. Firat, the South Korean
electronics industry is geared

for exports; the average Korean
can’t afford color TVs and VCRs.

Second, Samsung is a huge
company end a big experter to
U.S. department stores. For
example, many of the "no nase"
brand TVs in these stores are
Produced by Samsung. Finally,
although perhaps an unrelated
fact, the T/8 2068s were being
assembled in South Korea.
Conclusions-~I°11l imave you to
draw your own.

$e

ZEBRA JOYSTICK
by Will Stackean

The joystick adaptor available from
Zebra Systems of Woodhaven, N.Y. is an
easy~to-use hardware add-on driven by a
9 byte MC routine, compatible with Atari
type "sticks". With its routine in 1 REM,
the user can adapt any program where
INKEY$ would be used used to-accept an
input. Thus this interface could also
be used to accept up to 9 external switches
for same practical applications as well
as gaming. The device is well-made but
barely shielded. It is possible, to loosen
the connector socket connections which
are push-fit. There is no trouble plugging
additional peripherals onto the expansion
connector provided. The USR routine can
of course be located above RAMIOP allowing
a number of programs to be loaded under
it.

eee

ZxLRGS
by Will Gteckman

The leisurely LOADing speed of Sin-
clair computers has been a drawback
since their inception. Several systems
are available to overcome this handicap.
The ZXL8R program package from G.Russell is|
the most econamical and quite satisfactory.
Rather than depend on a hardware filter
or an elaborate checksum procedure, this
method of increasing LOADing speed first
has the user calibrate the program to a
particular cassette recorder. The data
received from the calibration program is
then used to adjust the main program when

LOADing or SAVEing.

The 2XL8R is actually a miniature oper-
ating system, allowing data as well as
program LOADs. Since ail programs must be
LOADed by title, there is also a utility
for scanning a tape to list all titles.

Use of this system takes some practice, but
the documentation is adequate. If programs
are SAVEd at lower calibration speeds (for
more reliability) there is a good chance
they can be reLOADed on similar machines.
Since, as the name implies, this program
speeds up the signal to the recorder, which
raises its pitch, the machine used must
have good treble tone and properly aligned
heads. Strangely enough, the Winky Board
doesn't seem to help when used with this
system.

Some NAMES
AT TIMEX

Here are a couple of useful
names of people who still work
at TIMEX Computers.

Elaine Cristille, 203-573-4815.
Elaine is involved with third
party documentation.

Cathy Hoolihan, 203-573-5246.
Cathy is the person to talk with
if you want to buy products
direct from TIMEX.

USSR Gta
by Mike Coughiin

So youve loaded the copy
Protected program you spent the
last month writing on your
TS1000/7ZX81, and it’s so well
protected that the keyboard
doesn’t work. Not only that but
you"ve enly got one copy. Serves
you right! But there’s a little
known trick (first described in
Syntax) that will come to the
rescue.

Ins d of using the normal LOAD
“name" comand, use a USR call.

The LOAD and SAVE routines are
unusual since thay require a
name string as input. The syntax
checker doesn’t like strings
after a USR call. But there are
two statements that will work.

LOAD CHR® USR B32 "name", or
SAVE CHR# USR 632 "name"

The USR B32 statement will start
the LOAD routine, the CHRE
converts whatever is left from
USR to an acceptable input to
LOAD and SAVE and the whole
combination gets past the syntax
checker. SAVE CHRS 632 "" is the
more usual form. First your
intractable program will be
loaded and before it can do any
funy busine: the save routine
will execute. If you’r@al quick
{you have five seconds) you can
switch tapes and make « copy.

As soon as you see the blank
screen and the pattern from the
SAVE routine, you can hit space
and the program will be loaded
but "unlocked" from any machine
code or BASIC statements that
normally run immediately. You
can LIST and change BASIC
statements, or refer to your
detailed notes and POKE
corrections to your machine
code. You did keep detailed
notes didn’t you?

The Boston Computer Society helps make sense
outof personal computers Ifyou'te interested in
computers for home, business or education, come to
‘The BCS for objyecuve information and support. The
BCS ts the largest nonprofit personal Computer agao-
cagian in the United States; our goal is not to pro-
foie ony particular brand of computer, but ta help
‘Computer users and people who just want to know
What 4 computer could do for them.

Sign me up for these userAnterest groups:

© Apple/Boston (Appie)

O ‘Atari User Group

© Business User Group

G Consultants & Entrepreneurs Interest Group

© Database User Croup

O Displaywriter User Group

Educational Resource Exchange

O 80/Boston (TRS-80)

© Family Home User Group

O Logo User Group

0 IBM User Group

G North Star User Group

© Osborne UserGroup |

© OSI/Boston (Ohio Scentfic)

© Pascal User Group

O PET/CBM/VIC User Group

O Roboncs Interest Group

x Sinclau/Timex User Group

Q Telecommunicatons User Group

8 The Boston
Computer Society

Three Center Plaza
Boston, MA 02108
617.367.8080

**# ZX PRO/FILE *#*
a 16K+ file manager for the Timex

ZX PRO/FILE is a machine language data base
that gives you tremendous versatility:

*instant access to any file stored in memory
*files of any size in the same program run
*singie or multiple word search capabilities
*ordered file displays

*comprehensive programmable printer functions

A 59 page manual comes with the cassette. In it
are complete instructions, examples, directions
for upgrading to larger memories, modifications,
program listings, and a detailed explanation of
how the program works. There's even an intro-
duction to machine coding for beginners.

ZX PRO/FILE is the best file manager you can
get for your Timex. In fact, users report that it
provides data handling functions found only on
the most sophisticated systems.

Prices just $16.95
Let me send you full specifications. Write to:
Thomas B. Woods

P.O, Box 64, Jefferson, NH 03583
Phone: (603) 586-7734